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20            MOEPHOLOGY AND EVOLUTION
bone Is present in Perodicticus and  CUromys.     The carpus has an os centrale.
The slender femur has a short, stout neck and three troehanters—the third trochanter being situated in the gtateal ridge. The upper end of the shaft is compressed antero-posterioriy, but the lower part is compressed transversely. The tibia and fibula are not fused dis-taliy as in Tarsim. The entocuneiform is rounded, and a saddle joint allows of free movements of the hallux. The OS calcis is prominent and the tarsus is Hat. The first metatarsal bone has a large tubercle for the tendon of the peroneus longus. thus suggesting that this muscle abducts the hallux (Duckworth).
The Muscular System.—The muscles have the same general arrangement as in Man, but they are disposed in a manner most suitable to the mode of life of the animal.
The platysma. has an extensive origin from the mid-dorsal line of the neck, as in many Carnivora, and it sweeps forwards to blend with other muscles at the angle of the mouth. Beneath it there lies a sheet of muscle with transverse fibres known as the sphincter colli. These muscles, likewise the dorso-humeralis, are parts of the cutaneous musculature. The.facial and auricular muscles are well marked.
The sternal and clavicular parts of the sterno-mastoid are slender, but the insertion into the occipital bone is , extensive.   The trapezius has no occipital origin as in &t e Gibbons, and the rhomboideus is strong and extensive. infra-hyoid muscles are not  peculiar, and  the V'c muscle is really monogastric (Parson's second Lemurs*/- ™as from the occipital bone behind to the